Ultrasonic Range Finder - The circuit is designed to be low cost. It uses a PIC12C508 to perform the control functions and standard 40khz piezo transducers. The drive to the transmitting transducer could be simplest driven directly from the PIC. The 5v drive can give a useful range for large objects, but can be problematic detecting smaller objects. The transducer can handle 20v of drive, so I decided to get up close to this level. A MAX232 IC, usually used for RS232 communication makes and ideal driver, providing about 16v of drive. __ Designed by Gerald Coe

Ultrasonic Range Finder & Imager - This is the electronic schematic of the homebuilt SONAR. Only one piezoelectric tranducer is used for both tramsmit & receive. This transducer is switched from TX to RX via the four 4016 switches. A high gain amplifier stage & rectifier translates the received echoes into voltage pulses. The timing is controlled by the PIC12C508 8-pin microcontroller __

Use a PIC for automatic baud-rate Detection - 08/22/02 EDN-Design Ideas Automatic baud-rate detection is desirable in many applications. Microchip's(www.microchip.com] standard USART module that the company embeds in most of its PIC microcontrollers lends itself to a simple and easily implemented automatic baud-detection scheme. The PIC18FXX2 data sheet defines the following baud rate in bits per second where X is the value for the baud-rate generator and FOSC__ Circuit Design by Ross Fosler, Microchip Technology, Chandler, AZ

Use a Printer Port to Record Digital Waveforms - 6/18/98 EDN-Design Ideas NOTE
: Page contains several ideas. Scroll for this one. To record or capture special waveforms, those that appear once or have no fixed frequency, the usual technique is to use a logic analyzer or a storage oscilloscope. However, these tools are very expensive. Moreover, because of limited memory, a storage scope can record fewer than 1000 samples. __ Circuit Design by Dean Shen, Dycam Inc, Chatsworth, CA

Use a Printer Port to Record Digital Waveforms - 06/18/98 EDN-Design Ideas (File includes several circuitsscroll to find this one) To record or capture special waveforms, those that appear once or have no fixed frequency, the usual technique is to use a logic analyzer or a storage oscilloscope. However, these tools are very expensive. Moreover, because of limited memory, a storage scope can record fewer than 1000 samples. The technique presented here provIdeas an alternative method to recording digital waveforms. The idea is to use the PC's printer port to sample waveforms, and the PC's memory to store data. __ Circuit Design by Dean Shen, Dycam Inc, Chatsworth, CA

Useless Masked µCS Make Useful PC Peripherals - 06/18/98 EDN-Design Ideas A software bug or a new code revision can often render hundreds of masked µCs all but useless for production purposes. However, by tapping into the 68HC11's bootstrap mode, you can attach these µCs to a PC's RS-232C serial port and put them to work. In the MC68HC11E9, 512 bytes of RAM are availableFile contains several Design Ideas, scroll to this one[Alec Bath, Motorola Inc, Northbrook, IL] __ Circuit Design by Alec Bath, Motorola Inc, Northbrook, IL

Using a 555 Timer as an A/D converter - Measure voltages accurately with a microcontroller using this simple circuit. Includes sample program for the Parallax Basic Stamp. __ Designed by Bob Blick

Voltage follower with 1G ohm input resistance - This is a new implementation of the AVR DDS signal generator v2.0, already published in scienceprog. com. It is obvious that full credit for the original schematic and the firmware goes to its original creator. Presented here is a different PCB that is compact, single sided with only through-hole components for easy construction. __ Designed by Vassilis Papanikolaouvpapanik @ gmail.com

Water-level Alert - This circuit will emit an intermittent beep (or will flash a LED) when the water contained into a recipient has reached the desired level. It should be mounted on top of the recipient (e.g. a plastic tank) by means of two crocodile clips, acting also as probes. If a deeper sensing level is needed, the clips can be extended by means of two pieces of stiff wire (see pictures). __ Contact: Flavio Dellepiane, fladello @ tin.it

Water-level Sensing & Control - This is a simple but reliable circuit for your sump-pump, aquarium, boat, or whatever, but water only. Please be careful when working with 115Volt line voltage! Take every precaution to avoid electrical shock. Unplug the power before making changes or touching resistor R1. Murphy's Law applies to all of us!. __ Designed by Tony van Roon VA3AVR

Weather Logger - Presented here is a personal weather logger whose various transducers are used to log weather data such as humidity, atmospheric pressure and temperature. The data is transferred to PC where it...___ Electronics Projects for You

Weather Station - Logging six temperatures and solar activity at one minute intervals around the clock using a 4 megabyte serial flash chip. The observation results are graphed to demonstrate weather conditions over multiple days in the Chicagoland area. Ran into some problems with a broken wire, overheating project box, shadows, and exposed sensors. __ Contact: David Cook

Wind speed logger - This wind logger project was designed to help a friend who wants to log wind speed for one year. It uses an inexpensive cup anemometer from Biral (see photo, left) available here in the UK. The anemometer contains a reed switch with rotating magnets which produce two switch closures per revolution of the cup assembly. __ Designed by Hans Summers

Wind speed logger Mk2 - Following quick on the heels of the Mk1 Windlogger project, I had built this new version which incorporates a host more features. The new version includes datalogging to an SD-card with Date/Time stamp as well as an onboard temperature sensor and light intensity sensor. External analogue inputs allow for logging wind direction too if your anemometer supports it. __ Designed by Hans Summers

Wireless Liquid Level Sensing for Restaurant Applications - Since restaurants often make much of their profits on drinks, it is critical for servers to offer
refills in a timely fashion. We propose wireless liquid level sensing glassware to aid in this task.
Specially instrumented glassware detects fluid levels via a high-resolution capacitance measurement.
A coil embedded in the table inductively couples power to the glasses, and provides a path
for data exchange. Our prototype glass uses a standard microprocessor and a small number of
passive components, making it extremely inexpensive. __ Designed by Paul H. Dietz; Darren Leigh; William S. Yerazunis

XBee ZNet 2.5 Wireless Accelerometer - I managed to put together a wireless accelerometer the other night using my two new XBees, an Arduino XBee shield, an XBee Explorer USB, an ADXL330, and some Python. I struggled a bit with some of it, __ Designed by Damon Kohler